Electro-magnetic dent puller



March 24, 1964 w. H. RICHEY ELECTRO-MAGNETIC DENT PULLER Filed July 18,1961 ///e//z BY @.2

United States Patent O 3,126,046 ELEC'IRQ-MAGNETHQ DENT FULLER WilliamH. Richey, London, Ohio (446 E. Church St, Marion, Ohio) Filed July 18,1961, Ser. No. 124,833 1 Claim. (ill. 1533-2) This invention relates toautomobile body repair tools, and more particularly to anelectro-magnetic apparatus for removing dents from automobile bodies orfenders, or from other articles constructed of similar magnetic sheetmaterial.

A main object of the invention is to provide a novel and improvedelectro-magnetic tool for use in straightening dented vehicle fenders,door panels, or other sheet metal areas of a vehicle body, or any otherobject.

A further object of the invention is to provide an improvedelectro-magnetic tool for straightening dents in sheet metal surfaces,said tool being relatively simple in construction, being easy tooperate, and enabling vehicle fenders, door panels, or other bodyportions to be straigh ened without the necessity of drilling holestherein or of using hooks, pry bars, or other auxiliary tools.

Further objects and advantages of the invention will become apparentfrom the following description and claim, and from the accompanyingdrawings, wherein:

FIGURE 1 is a longitudinal vertical cross sectional view taken throughan improved electro-magnetic dent puller constructed in accordance withthe present invention, shown positioned in operative relationship withrespect to a body panel area to be straightened.

FIGURE 2 is a transverse vertical cross sectional view takensubstantially on the line 22 of FIGURE 1.

FIGURE 3 is a perspective view of the tool shown in FIGURES 1 and 2.

Referring to the drawings, the improved electro-magnetic dent pullingtool is designated generally at 11 and comprises a generally cylindricalelongated main body portion 12 which is integrally formed at one endthereof with a transversely extending hollow handle 13 which extends onopposite sides of the end of the sleeve-like main body 12 so as toprovide a grip for both hands of the operator using the implement. Toimprove the grip on the laterally projecting portions of the hollowhandle 13, the inside surfaces of said laterally projecting portions aresinuously curved, as shown at 14.

The outer side of the handle 13 is integrally formed at its centerportion with a supporting eye member 15 which may be employed to supportthe implement from a suitable hook, or the like, when not in use.

Designated at 17 is an end cap which is threadedly en gaged on the endof the main sleeve-like housing 12 opposite the handle 13, said cap 17being provided with a knurled outer surface 18 to facilitate the manualsecurement of the cap on the end of the member 12. Rigidly secured inthe end portion of the sleeve-like housing 12 is a transverse wall 19,and secured thereto in side-byside relationship are a pair ofelectro-magnets 2t), 2t) said electro-magnets having hollow cores 21through which extend the respective axial securing bolts 22. Thesecuring bolts 22 have beveled heads which engage in suitablecountersunk central openings in the front core flanges 23 of theelectro-magnets, the bolts extending through the fixed wall 19 and beingfastened thereto by suitable nuts 24, as shown in FIGURE 1. Integrallyformed with the wall 19 is a spacer plate 26 which extends between theside-by-side electro-magnets 2t), 26 and which merges with thediametrically opposite peripheral portions of the cap 17, as is clearlyshown in FIGURE 3.

The electro-magnets 2h, are connected together in series and are soarranged that a north pole is produced at the face 23 of one of theelectro-magnets while a south pole is produced at the face 23 of theother when the magnets are energized. The terminal wires of theseriesconnected magnets extend through and are insulated from thepartition wall 19, said wires being shown at 27 and 28. The wires 27 and28 are connected respectively to the terminals of the secondary windingof a step-down transformer 29 which is mounted in the sleeve-like mainhousing 12, as shown in FIGURE 1.

A supply cord Si) is provided, said cord extending through a flexiblesupporting sleeve 31 secured in the ends of one of the laterallyprojecting arms of the handle 13, the wires of the supply cord beingconnected respectively to the terminals of the primary winding of thetransformer 29 through a control switch 32. Thus, one of the supplywires, shown at 33, is connected directly to a terminal of the primarywinding of transformer 29, and the other supply wire, shown at 34, isconnected to one of the terminals of the control switch 32, the oppositeterminal of the control switch being connected by a wire 35 to theremaining terminal of the primary winding of the transformer 29. Thecontrol switch 32 is mounted in the end portion of the sleeve-likehousing 12, as shown in FIGURE 1, and is provided with an operatingtrigger member 36 which projects externally and which extends into thespace defined within a trigger guard 38 provided between one of thelaterally projecting arms of the handle 13 and the adjacent end portionof the sleeve-like main housing 12.

As will be readily apparent, by employing the stepdown transformer 29, ahigh current may be provided in the secondary circuit including theelectro-magnets 20, 20 at low voltage, so that the primary current inthe supply wires 33 and 34 is held to a reasonable value.

In using the tool, a back-up block 40 is employed behind the sheet metalportion 41 to be straightened, the block 463 being of magnetic materialso as to cooperate with the sheet metal portion 41 to provide a regionwhere high fiux concentration can be obtained. With the switch 32closed, the electro-magnets 26, 2% are energized so that the fluxdeveloped thereby flows through the sheet metal portion 41 and theback-up block 4h, providing strong adhesion of the implement to thesheet metal portion 41. The sheet metal portion may then be pulledoutwardly by exerting outward force on the laterally projecting arms ofthe handle 13, enabling the portion 41 to be accurately and efiicientlystraightened, without the necessity of exerting hammer blows on theinside of the sheet metal portion 41, or of drilling holes for theinsertion of pry bars, hooks or other implements.

It will be understood that in using the implement, the normal techniquerequired in dent straightening must be employed. Thus, theelectro-magnetic head portion of the tool must first be applied to theouter edge of the dent and the outer edge portion of the dent must thenbe pulled out by the physical force of the workman. The remainingportions of the dented area may then be straightened by following theusual procedure.

In using the device on large dented areas, the tool may be employed toprovide an electro-magnetic connection to a central area of the panelportion to be straightened, so that outward force may be applied to saidcentral area by pulling outwardly on the tool with one hand, and asuitable tool, such as a slapping spoon may be employed to apply impactto the outer edges or ridge of the dent. In such a procedure, in manycases, the central portion of the dent will pop out to its proper shapewithin a very short time after starting the straightening operation.

An auxiliary mechanical pulling or leverage device may be employed withthe tool, whenever required, by connecting same to the supporting ring15. Thus, the

outward pull may be applied to the tool by the auxiliary pulling orleverage device by means of its fastening to the ring 15, while the usermerely holds the switch 32 closed to maintain the electro-rnagneticattachment of the tool to the portion of the panel to be straightened.

While a specific embodiment of an improved dent pulling tool has beendisclosed in the foregoing description, it will be understood thatvarious modifications within the spirit of the invention may occur tothose skilled in the art. Therefore, it is intended that no limitationsbe placed on the invention except as defined by the scope of theappended claim.

What is claimed is:

An electro-magnetic dent puller comprising an elongated main housinghaving a transverse hollow handle at one end, a transverse partitionwall in the main housing adjacent to and spaced inwardly from its otherend, a longitudinal partition wall in said main housing secured to saidtransverse partition wall and extending to said other end defining apair of side-hy-side compartments at said other end of the main housing,respective electromagnets disposed in said compartments and havinghollow longitudinally extending cores, respective bolts in said coresextending axially therethrough and through said transverse partitionwall and securing the electromagnets thereto, said bolts having headsexposed at said other end of the main housing and flush with the endfaces of the electro-rnagnets at said other end, means connecting saidelectro-magnets in series and so that the end faces of theelectro-magnets adjacent the bolt heads will have opposite magneticpolarity when the electro-magnets are energized, a step-down transformermounted in the housing, means connecting the secondary of thetransformer to the series-connected electro-magnets, a control switchmounted in the housing and having an externally projecting operatingelement located adjacent the handle, and a line cord extending throughthe handle and connected to the primary of the transformer through saidcontrol switch.

Sanchez Aug. 5, 1952 Crowder Dec. 7, 1954

